1. Field Of The Invention
The present invention relates to isoquinoline derivatives. More particularly, the present invention is concerned with isoquinoline derivatives which are novel compounds that affect the vascular smooth muscle of a mammal, thereby being of value as, e.g., vasodilators, cerebral circulation ameliorators, and drugs for prevention and treatment of angina, myocardial infarction, cerebrovascular thrombosis, cardiovascular thrombosis, hypertonia and other circulatory organ diseases. The isoquinoline derivatives of the present invention also affect the bronchial smooth muscle of a mammal, thereby being valuable drugs for prevention and treatment of respiratory organ diseases such as asthma.
2. Discussion Of Related Art
Known in the art are compounds useful to treat circulatory organ diseases which are represented by the following formulae (II) to (IX): ##STR2## In the above formulae, R.sup.6 represents an alkyl group, an aryl group, an aralkyl group, a benzoyl group, a cinnamyl group, a furoyl group or a group of the formula: ##STR3## in which R' represents a lower alkyl group. R.sup.7 and R.sup.8 each independently represent a hydrogen atom or a lower alkyl group, or R.sup.7 and R.sup.8 are bonded with each other directly or through the medium of an oxygen atom or a nitrogen atom to form a heterocyclic ring in cooperation with the adjacent nitrogen atom. R.sup.9 represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. R.sup.10 represents a group selected from alkyl, aryl and aralkyl groups each having 1 to 10 carbon atoms, and R.sup.11 represents a hydrogen atom or a group selected from alkyl and aryl groups each having 1 to 10 carbon atoms. R.sup.12 and R.sup.13 each independently represent a hydrogen atom or a group selected from alkyl, aryl and aralkyl groups each having 1 to 10 carbon atoms, or R.sup.12 and R.sup.13 are bonded with each other directly or through the medium of an oxygen atom to form a heterocyclic ring in cooperation with the adjacent nitrogen atom. Symbols m and n each independently represent an integer of 0 to 10. B represents an alkylene group having v carbon atoms substituted with u group(s) selected from alkyl, aryl and aralkyl groups each having 1 to 10 carbon atoms, in which v is an integer not greater than 10 and u is an integer of 0 to 2.times.v. R.sup.14 and R.sup.15 each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, or R.sup.14 and R.sup.15 are directly bonded with each other to form an alkylene group having 2 to 6 carbon atoms. D.sup.1 represents an ethylene group substituted with x alkyl group(s) each having 1 to 6 carbon atoms, in which x is an integer of 0 to 4. D.sup.2 represents an ethylene or trimethylene group each substituted with y alkyl group(s) each having 1 to 6 carbon atoms, in which y is an integer of 0 to 4. R.sup.16 and R.sup.17 each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, or R.sup.16 and R.sup.17 are directly bonded with each other to form an alkylene group having 2 to 4 carbon atoms. E represents an alkylene group having 2 to 6 carbon atoms and unsubstituted or substituted with an alkyl group having 1 to 6 carbon atoms. R.sup.18 and R.sup.19 each independently represent a hydrogen atom, a straight chain or branched alkyl group having 1 to 6 carbon atoms, or R.sup.18 and R.sup.19 are directly bonded with each other to form an ethylene or trimethylene group each unsubstituted or substituted with an alkyl group having 1 to 6 carbon atoms. R.sup.20 represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms or an amidino group. R.sup.21 represents a hydroxyl group or a chlorine atom. F represents an ethylene group unsubstituted or substituted with an alkyl group having 1 to 6 carbon atoms, a phenyl group or a benzyl group. G represents a trimethylene group unsubstituted or substituted with an alkyl group having 1 to 6 carbon atoms, a phenyl group or a benzyl group. R.sup.22 represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.
The above compounds may effectively increase the diameter of cerebral blood vessels. However, although the compounds effectively act on cerebral blood vessels, they have poor activity with regard to increasing the diameter of cardiac blood vessels. Hence, there is still a strong demand in the art for compounds which can more effectively increase the diameters of both cerebral and cardiac blood vessels.